Discriminator does not show up on intermediate type

[weirdan]

Consider the following type hierarchy:

which is fairly classic example of a "diamond inheritance", possible in languages that support multiple inheritance.
It could be expressed with allOf & enum in the following way:

  "definitions": {
    "BaseRef": {
      "type": "object",
      "discriminator": "type",
      "required": [ "type" ],
      "properties": {
        "type": {
          "type": "string",
          "enum": [ "BaseRef",  "Base", "ChildRef", "Child" ]
        }
      }
    },
    "Base": {
      "allOf": [
        { "$ref": "#/definitions/BaseRef" },
        {
          "type": "object",
          "required": [ "type" ],
          "properties": {
            "type": {
              "type": "string",
              "enum": [ "Base", "Child" ]
            }
          }
        }
      ]
    },
    "ChildRef": {
      "allOf": [
        { "$ref": "#/definitions/BaseRef" },
        {
          "type": "object",
          "required": [ "type" ],
          "properties": {
            "type": {
              "type": "string",
              "enum": [ "ChildRef", "Child" ]
            }
          }
        }
      ]
    },
    "Child": {
      "allOf": [
        { "$ref": "#/definitions/ChildRef" },
        { "$ref": "#/definitions/Base" },
        {
          "type": "object",
          "required": [ "type" ],
          "properties": {
            "type": {
              "type": "string",
              "enum": [ "Child" ]
            }
          }
        }
      ]
    }
  }

When Base is referenced I'd expect it to display selector for type field, as Base is a part of inheritance hierarchy, listing everything BaseRef selector would list, additionally filtered by enum list. Basically, selector should be inherited.

It might be tempting to constraint the selector by the current and all "descendant" types, as to not require enums, but that would prevent using definitions as genuine constraints (which they really are), ruling out the possibility to use something like this:

    "RefOnly": {
      "allOf": [
        { "$ref": "#/definitions/BaseRef" },
        {
          "type": "object",
          "required": [ "type" ],
          "properties": {
            "type": {
              "type": "string",
              "enum": [ "BaseRef", "ChildRef" ]
            }
          }
        }
      ]
    }

Here, RefOnly ensures that wherever it's used only BaseRef and ChildRef are accepted (forbidding Child and Base, even though they are compatible with BaseRef), it's not used as a subclass. If the selector would show descendants here it would show nothing, as BaseRef could not be made to "inherit" RefOnly, as that would create circular dependency.

Live demo

swagger.json

[RomanHotsiy]

@weirdan thanks for the very detailed bug report and for the minimal reproducible sample! This is the best ReDoc issue report so far 🥇!

This is a valid issue but I have to complete "CS143: Compilers" course in order to fix it 😂

On the serious side, this is a pretty complicated use case. I will try to fix this but after releasing ReDoc 2.0 (React rewrite).

[weirdan]

Any ideas on when react-rewrite could land? On the orders of magnitude scale, is that months or years?

[RomanHotsiy]

I would say weeks! You can track this issue to staying tuned: #327

[RomanHotsiy]

Closing as stale. Please reopen if this still is actual for you.